Ameliorating electronic/ionic transport and structural stability of electrode materials is important to the development of power‐intensive lithium ion batteries. Despite its great potential as a high‐power anode, titanium niobium oxide (Ti2Nb10O29, TNO) still underperforms due to its unsatisfactory electronic/ionic conductivity. In this work, a powerful synergistic strategy by combining ion doping and spiral array architecture to boost high‐rate performance of TNO is reported. Cr3+ doped TNO nanoparticles (Cr‐TNO) of 5–10 nm intimately grow on a conductive vertical graphene @TiC‐C (VGTC) skeleton, forming novel Cr‐TNO @VGTC spiral arrays. The unique spiral growth of TNO is achieved due to the confinement effect of VGTC skeleton. Meanwhile, a more open TNO crystal structure with faster ion transfer paths and enhanced structural stability is realized by Cr3+ doping, demonstrated via density functional theory calculation and in situ synchrotron X‐ray diffraction technique. Benefiting from the superior conductive network, enhanced intrinsic electronic/ionic conductivity of Cr‐TNO and reinforced structural stability, the Cr‐TNO @VTC arrays show prominent high‐power performance with a large capacity of 220 mAh g−1 at 40 C (power density of ≈11 kW kg−1) and superior durability (91% retention after 500 cycles). This work provides a new path for the construction of widespread high‐power electrodes for fast energy storage.
Read more at Advanced Functional Materials :
https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.202002665?af=R
29 Apr 2020